ABSTRACT
Oxidation-reduction (redox) reactions play a critical role in physiological systems and pathological states. An imbalance between free radicals and antioxidants in the human body is termed as oxidative stress. Impaired homeostasis of reactive oxygen species (ROS) is the leading cause of several diseases and disorders including cancer. Metals and metalloids play pivotal roles as active molecules that participate in several physiological processes including redox pathways. While some directly act as antioxidants or pro-oxidants, others may indirectly contribute to induction or relief from oxidative stress. Roles of some important metals and metalloids in oxidative stress, ROS generation and their implications in physiology and pathological states are discussed in this chapter.
